1. Field
Example embodiments relate to a method of forming an active region structure.
2. Description of Related Art
In general, semiconductor etching and photolithography processes involve transferring mask patterns of a photomask onto a semiconductor substrate using photolithography and etching apparatuses. To do this, the photoresist apparatus may form aerial images of the mask patterns on a photoresist layer of the semiconductor substrate. The semiconductor photolithography process may be performed to form photoresist patterns corresponding to the aerial images on the semiconductor substrate. The etching apparatus may transfer the photoresist patterns onto or into the semiconductor substrate using an etchant. The semiconductor etching process may be performed to form structures on or in the semiconductor substrate using the photoresist patterns.
In this case, as a semiconductor device design rule becomes smaller, a quality of the images formed by the photolithography apparatus on the photoresist layer may be reduced. This is because the images of the photolithography apparatus may be affected by interference of light beams crossing the mask patterns through the reduction in the design rule of the semiconductor devices. In addition, a quality of structures formed by the etching apparatus on or in the semiconductor substrate according to the photoresist patterns may be reduced. This is because the structures may be etched at different rates from one another by depending on the exposed areas of the upper portion of the semiconductor substrate.